update README

README.md

@@ -4,7 +4,7 @@ Provides SPI driver for SX1276/SX1278 LoRa radio
 
 ## Install
 
-Designed to be used as `esp-idf component`. Suggested using as `git submodule`
+Designed to be used as an `esp-idf component`. Suggested usage is with  `git submodule`
 
 ```
 git submodule add https://gitlab.com/morganrallen/esp32-lora.git components/esp32-lora/
@@ -14,38 +14,63 @@ git submodule update
 
 ## Configure
 
-Uses built in KConfig. Run `make menuconfig` and find config under `Component config` -> `LORA32`.
+Uses built in KConfig for configuration.
+Run `make menuconfig` and find config under `Component config` -> `LORA32`.
 Defaults targeted to TTGO LoRa OLED boards.
 
 ## Use
 This is the most basic usage. Setting up the LoRa instance, setting it's receive handler, running init then sending a message.
 
 ```
+  #include <stdio.h>
+  #include <string.h>
+
+  #include "esp32-lora.h";
+
   lora32_cfg_t lora;
-  lora = lora32_create();
-  lora.receive = &handle_lora_receive;
 
-  lora32_init(&lora);
+  static void handle_lora_receive(uint8_t size) {
+    char *message = malloc(size+1);
 
-  lora32_send(&lora, "Hello, LoRa", 11);
+    lora32_read_data(&lora, message);
+
+    // ensure null termination
+    message[size] = '\0';
+    
+    printf("msg: %s\n", message);
+  }
+
+  void app_main() {
+    lora = lora32_create();
+    lora.receive = &handle_lora_receive;
+
+    lora32_init(&lora);
+
+    lora32_send(&lora, "Hello, LoRa", 11);
+  }
 
 ```
 
 ## API
 
-### `lora32_cfg_t static lora32_create()`
-Creates a new LoRa instance
+### `static lora32_cfg_t lora32_create()`
+Creates a new LoRa instance.
 
 ### `uint8_t lora32_init(lora32_cfg_t *config)`
-Initialized LoRa instance. This configures GPIOs, SPI, LoRa radio and receive handlers
+Initialized LoRa instance. This configures GPIOs, SPI, LoRa radio and receive handlers.
 
 Returns 1 on success.
 
+### `void lora32_set_coding_rate(lora32_cfg_t *lora, uint8_t d)`
+Set `Coding Rate`.
+
+Accepts `5`-`8`.
+
 ### `uint8_t lora32_data_available(lora32_cfg_t *lora)`
-Indicates if data is presently available.
+Returns number of bytes available in FIFO buffer.
 
 ### `void lora32_send(lora32_cfg_t *config, uint8_t *data, uint8_t len)`
-Transmits data over the LoRa radio.
+Transmits data over the LoRa radio. Puts `DIO0` into `TXDONE` mode.
 
 ### `void lora32_set_spreadfactor(lora32_cfg_t *lora, uint8_t factor)`
 Sets LoRa Spread Factor.
@@ -53,4 +78,40 @@ Sets LoRa Spread Factor.
 Accepts `6`-`12`.
 
 ### `void lora32_dump_regs(lora32_cfg_t *lora)`
-Dumps all registers from SX1276
+Dumps all registers from SX1276.
+
+### `void lora32_read_data(lora32_cfg_t *lora, uint8_t *data)`
+Reads data out of FIFO buffer. This would typically be called after the callback `received` is triggered.
+
+### `void lora32_enable_continuous_rx(lora32_cfg_t *lora)`
+Enables continuous receive mode. If a receive callback has been setup, it will be trigger
+on any incoming data until either an `OP_MODE` or `DIO0` mode are change.
+
+### `void lora32_enable_single_rx(lora32_cfg_t *lora)`
+* **NOTE** This requires `DIO1` for complete functionality.
+* **NOTE** Implenentation incomplete.
+
+Enables single receive mode. Will either trigger `RXDONE` on `DIO0` or `RXTIMEOUT` on `DIO1`
+
+### `void lora32_enable_cad(lora32_cfg_t *lora)`
+Enables Channel Activity Detection. Will trigger callback `cad_done` with `bool detected` on completion.
+If activity was detected, it will also trigger `cad_detected`
+
+
+## Callbacks
+`lora32_cfg_t` provides several callbacks based on `DIO0` interrupts. Most functionality is provided through
+these, favoring async operations over syncronous polling.
+
+### `lora32_cfg_t->receive(uint8_t size)`
+Triggered from `RXCONTINUOUS` and `RXSINGLE` modes. Provides the number of bytes available. Should be followed
+up with a call to `lora32_read_data` to retrieve data from FIFO buffer.
+
+### `lora32_cfg_t->tx_done()`
+Triggers after call to `lora32_send` completes, as long as `DIO0` mode has not been changed.
+
+### `lora32_cfg_t->cad_done(bool detected)`
+Triggers after call to `lora32_enable_cad` completes (ie times out) or channel activity is detected.
+`bool detected` will reflect these two states.
+
+### `lora32_cfg_t->cad_detected()`
+Triggers after call to `lora32_enable_cad` successfully detects channel activity.